Electrical call-bell.



No..715,683'. Patented Dec. 9, |902.

` w. E. mconmcx. ELEcTlcAL GALL BELL.

[.Appusin med me. 16, 190m' (lo Modal.)

1u: man@ MUERE w, Pham-Lune., WASHINGTQN. u. c.

UNITED STATES PATENT` OFFICE.

WILLIAM E. MCCORMICK, OF CHICAGO, ILLINOIS, ASSIGNOR TO INTER- NATIONALTELEPHONE MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OFILLINOIS.

ELECTRICAL CALL-BELL.

SPECIFICATION forming part of Letters Patent N 0. 715,683, datedDecember 9, 1902. Application filed December I6, 1901. Serial No.86.031. (No model.)

T0 all whom it may concern:

Be it known that I, WILLIAM E. MCCOR- MICK, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements inElectrical Call-Bells, (Case No. 10,) of which the following is aspecification.

My invention relates to electrical call-bells, and particularly to suchdevices of this type as are employed in telephone work; and it is theobject of the invention to simplify the construction of the apparatusnow in use and to render it more effective for the purpose of receivingsignals or calls.

In the drawings which form a part of this specification, Figure l is anelevation of the ringer constructed according -to my invention. Fig. 2is a detail View, partly in section, showing the means for attaching thearmature plate or bar and for adjusting the same; and Fig. 3 illustratesa modification of the means for adj ustably connecting the hammer-wireand the armature-plate.

In constructing my improved ringer the electromagnets M are connected inseries and are included in the line or in a local circuit in the usualway and preferably are wound to a resistance of about sixteen hundredohms-that is, of course, eight hundred ohms for each spool. The cores cof these bellmagnets are fixed on the frame A by means of a heel-pieceA, as usual, which also serves as a part of the ringer-frame. Apermanent magnet N of the usual form is also secured on the frame in anysuitable manner, so as to polarize the two cores cwith one polarity andthe central pivoted armature awith an opposite polarity. The armature islpivoted between central front and rear lugs ct of the bar A2 of theframe in the usual manner and carries the bell-ham mer wire or rod 0,2,which vibrates between the bells or gongs B, as usual. The armature isprovided with a suitable socket a3 in its pivotal line in which the rodor Wire a2 is adjustably supported, whereby the ball at the end of thesame may be positioned at the correct location to strike the bells orgongs at the edge. This adjustment 5o may be effected by anysuitable'means, such as the screw-thread connection shown in Fig. l orthe set-screw shown in Fig. 3. The rod or wire is also provided with acurl or spring a4, whereby greater extent of vibration of the ball issecured.

The plate or bar A2 is rigidly secured at one end upon one of the sidepieces of the frame by any suitable means, such as a binding-nut a5, andis adjustably attached at its other end to the opposite side of theframe in order to vary and adjust the position of the armature withrelation to the cores of the bell-magnets in order to get a longer orshorter throw of the wire or rod 0.2. For this purpose the plate or barA2 is preferably constructed of spring metal and is provided at its freeend with a suitable slot or perforation to allow it to pass freely overthe screw-threaded end a of the associated side piece of the frame. Apair of oppositely-disposed threaded thumb-nuts a7 and as serve to bindit in any adjusted position.

yIt is desirable in this class of devices to adjust the armature closeto the cores, as it is well known that better results and moresatisfactory work follow such relations of the parts. By my improvedconstruction this adjustment may be regulated toand maintained at thepoint of highest efficiency, While the curl or spring in the rod orwire, which allows greaterextent of vibration of the hammer or ball atits end, permits this adjustment to be made without limiting orimpairing the Vibration of the rod and the sounding of the signal.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is

l. In an electricalcall-bell, the combination with a ringer-framesupporting electromagnetic devices, of an armature-plate rigidly securedto said frame at one end and adjustably supported on said frame at itsother end.

ICC

3. In an electrical call-bell, the combination having an adjustableconnection With said ai'- With a ringer-frame having a. threaded sidemature. piece, and eleotromagnets mounted on the In testimony whereof Iaffix my signature f1'ame,ofan armature pivotallymounted upon inpresence of two Witnesses. an armature-plate, said armature-plate beingWILLIAM E. MCCORMICK. rigidly secured to said frame at one end andWitnesses: adjustable upon said threaded side piece by R. K. GUSTAFSON,means of thu mb-nuts, and a hammer-stem J. MCROBERTS.

